Agricultural vehicles are used more on asphalt roads and needs to be safe in an evasive maneuver or during an emergency brake scenario. The designers of these vehicles require tyre parameterization data to obtain accurate and representative simulation results of these vehicles. The standard laboratory tyre testing procedures are not always possible on very large tyres. The limitations in the form of the actual size of the tyre and the required loads on the tyre cannot always be accommodated by the current equipment available to conduct dynamic tests. This study investigates how the tyre parameterization results compare between a dynamic/rolling tyre test and a static/non-rolling tyre. This is in an attempt to parameterize tyre models using largely or only static test data. Tests are conducted on a smaller agricultural tyre where dynamic tyres test results are compared to static tests.
{"title":"Tyre Parameterization Tests: Dynamic vs. Static","authors":"C. Becker, S. Els","doi":"10.56884/vtfc7095","DOIUrl":"https://doi.org/10.56884/vtfc7095","url":null,"abstract":"Agricultural vehicles are used more on asphalt roads and needs to be safe in an evasive maneuver or during an emergency brake scenario. The designers of these vehicles require tyre parameterization data to obtain accurate and representative simulation results of these vehicles. The standard laboratory tyre testing procedures are not always possible on very large tyres. The limitations in the form of the actual size of the tyre and the required loads on the tyre cannot always be accommodated by the current equipment available to conduct dynamic tests. This study investigates how the tyre parameterization results compare between a dynamic/rolling tyre test and a static/non-rolling tyre. This is in an attempt to parameterize tyre models using largely or only static test data. Tests are conducted on a smaller agricultural tyre where dynamic tyres test results are compared to static tests.","PeriodicalId":447600,"journal":{"name":"Proceedings of the 11th Asia-Pacific Regional Conference of the ISTVS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128275051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wheeled vehicles are the most convenient and widespread locomotion machines for the majority of research, industrial or private tasks. A perceptible share of wheeled vehicles is used on soft soil. Modelling wheel locomotion in these situations is challenging, because of the non-proportional relation between applied shear stress and the soil’s deformation. Currently, various conventional simulation approaches are used to describe wheel–soil interaction, ranging from detailed numerical methods with particle-level simulations to simpler empirical models, where a big part of physical formulas are set up a priori, empirically. The ultimate wheel locomotion modelling tool should have high-quality onboard predictions but within a reasonable time. The trade-off is unachievable with the current simulation tools. In this project, we argue that using Machine Learning (ML) we can build a tool with the quality of high-fidelity and speed of lower-fidelity simulations. To fit this requirement, we are combining data from several models with different fidelities, in order to build a multi-fidelity ML model. In the model, forces and torques acting on the wheel are predicted using input data like the wheel’s trajectory, surface and soil characteristics. The quality of this model will be validated by Terramechanics Robotics Locomotion Laboratory (TROLL) at Deutsche Zentrum für Luft- und Raumfahrt (DLR), a robotic single-wheel test bed designed to perform wheel–soil interaction experiments automatically. Early results show that, in simplified scenarios, our proposed method can be used to create efficient, multi-fidelity numerical models for locomotion prediction, including uncertainty estimation for the predictions.
{"title":"Multi-Fidelity Machine Learning Modeling for Wheeled Locomotion on Soft Soil","authors":"Vladyslav Fediukov, Felix Dietrich, Fabian Buse","doi":"10.56884/wgpv6693","DOIUrl":"https://doi.org/10.56884/wgpv6693","url":null,"abstract":"Wheeled vehicles are the most convenient and widespread locomotion machines for the majority of research, industrial or private tasks. A perceptible share of wheeled vehicles is used on soft soil. Modelling wheel locomotion in these situations is challenging, because of the non-proportional relation between applied shear stress and the soil’s deformation. Currently, various conventional simulation approaches are used to describe wheel–soil interaction, ranging from detailed numerical methods with particle-level simulations to simpler empirical models, where a big part of physical formulas are set up a priori, empirically. The ultimate wheel locomotion modelling tool should have high-quality onboard predictions but within a reasonable time. The trade-off is unachievable with the current simulation tools. In this project, we argue that using Machine Learning (ML) we can build a tool with the quality of high-fidelity and speed of lower-fidelity simulations. To fit this requirement, we are combining data from several models with different fidelities, in order to build a multi-fidelity ML model. In the model, forces and torques acting on the wheel are predicted using input data like the wheel’s trajectory, surface and soil characteristics. The quality of this model will be validated by Terramechanics Robotics Locomotion Laboratory (TROLL) at Deutsche Zentrum für Luft- und Raumfahrt (DLR), a robotic single-wheel test bed designed to perform wheel–soil interaction experiments automatically. Early results show that, in simplified scenarios, our proposed method can be used to create efficient, multi-fidelity numerical models for locomotion prediction, including uncertainty estimation for the predictions.","PeriodicalId":447600,"journal":{"name":"Proceedings of the 11th Asia-Pacific Regional Conference of the ISTVS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131170961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reconfigurable wheel-tracked system, which enables a vehicle to have the high speed of wheels and the increased mobility of tracks, is one of the key technologies on improving the off-road performance of vehicles in extreme environment. A series of such systems has already been developed and equipped on robots and medium or heavy ground vehicles. The paper reviews the research work, prototype and application of reconfigurable wheel-tracked systems. To start with, different systems are classified according to their mechanical structures. Development and current research interests are then reviewed. Triangle track configuration is the most prevalent layout of the wheel-tracked system, so this paper highlights its structure characteristics, research contents and applications. Following the review, key technologies such as design of power transmission system, mobility validation and elastic track design are analyzed. Finally, prospective of the reconfigurable wheel-tracked locomotion system is discussed in terms of transformation principle innovation, depth of research and width of application.
{"title":"Review of the Reconfigurable Wheel-Tracked System","authors":"Jiaxuan Wang, Cheng Liu, Q. Yan","doi":"10.56884/cxrt8456","DOIUrl":"https://doi.org/10.56884/cxrt8456","url":null,"abstract":"Reconfigurable wheel-tracked system, which enables a vehicle to have the high speed of wheels and the increased mobility of tracks, is one of the key technologies on improving the off-road performance of vehicles in extreme environment. A series of such systems has already been developed and equipped on robots and medium or heavy ground vehicles. The paper reviews the research work, prototype and application of reconfigurable wheel-tracked systems. To start with, different systems are classified according to their mechanical structures. Development and current research interests are then reviewed. Triangle track configuration is the most prevalent layout of the wheel-tracked system, so this paper highlights its structure characteristics, research contents and applications. Following the review, key technologies such as design of power transmission system, mobility validation and elastic track design are analyzed. Finally, prospective of the reconfigurable wheel-tracked locomotion system is discussed in terms of transformation principle innovation, depth of research and width of application.","PeriodicalId":447600,"journal":{"name":"Proceedings of the 11th Asia-Pacific Regional Conference of the ISTVS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130853598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development of high-performance mobile transport complexes for agricultural purposes is largely based on the results of scientific research. The main direction is to study the mobility properties of robotic complexes in specific natural and climatic conditions of the area. The purpose of this work is to determine the cone index CI for typical surfaces of agricultural machinery movement, based on the physical and mechanical characteristics of agricultural soils. In 2020 year, a large-scale experimental and theoretical study of agricultural soils was conducted for 7 months using a soil penetrometer and equipment for measuring soil density and humidity. The peculiarity of this work is that the study has a spatiotemporal character of changes in the mechanical parameters of soils. Thus, the cone index CI is determined during the agricultural season for five typical plots: the first plot is fallow land located on a slope; the second plot is virgin land; the third section is a plowed field; the fourth section is a dirt road and the fifth section is a dirt road covered with broken bricks. Thus, the study showed a change in the cone index for each site during the year: the first site – 4.8-10.93 kPa; the second site – 5.13-5.32 kPa; the third site – 4.14-4.57 kPa; the fourth site - 4.43 – 11.20 kPa; the fifth site – 5.57 – 5.81 kPa. The data were also approximated and a mathematical model for calculating the cone index from the deformation modulus E, (MPa) was obtained. The obtained mathematical dependencies can be used in the future as the basis for mapping the mobility of any region of the world, as well as in the compilation of the algorithm of the mobile robotic complex.
{"title":"Investigation of the Relationship between the Cone Index and the Physical and Mechanical Parameters of the Soil of Typical Surfaces of the Movement of Agricultural Tractors and Machines","authors":"S. Zhukov, V. Makarov, V. Belyakov, A. Belyaev","doi":"10.56884/vnzq2520","DOIUrl":"https://doi.org/10.56884/vnzq2520","url":null,"abstract":"The development of high-performance mobile transport complexes for agricultural purposes is largely based on the results of scientific research. The main direction is to study the mobility properties of robotic complexes in specific natural and climatic conditions of the area. The purpose of this work is to determine the cone index CI for typical surfaces of agricultural machinery movement, based on the physical and mechanical characteristics of agricultural soils. In 2020 year, a large-scale experimental and theoretical study of agricultural soils was conducted for 7 months using a soil penetrometer and equipment for measuring soil density and humidity. The peculiarity of this work is that the study has a spatiotemporal character of changes in the mechanical parameters of soils. Thus, the cone index CI is determined during the agricultural season for five typical plots: the first plot is fallow land located on a slope; the second plot is virgin land; the third section is a plowed field; the fourth section is a dirt road and the fifth section is a dirt road covered with broken bricks. Thus, the study showed a change in the cone index for each site during the year: the first site – 4.8-10.93 kPa; the second site – 5.13-5.32 kPa; the third site – 4.14-4.57 kPa; the fourth site - 4.43 – 11.20 kPa; the fifth site – 5.57 – 5.81 kPa. The data were also approximated and a mathematical model for calculating the cone index from the deformation modulus E, (MPa) was obtained. The obtained mathematical dependencies can be used in the future as the basis for mapping the mobility of any region of the world, as well as in the compilation of the algorithm of the mobile robotic complex.","PeriodicalId":447600,"journal":{"name":"Proceedings of the 11th Asia-Pacific Regional Conference of the ISTVS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124481418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The capacity of soil-burrowing animals to move freely in sticky soil is a motivational trait for developing soil engaging tools with high operational efficiency. The hydrophobicity and morphological profiles of soil animals' skin were reported to be the key pillars in producing their anti-adhesive mechanisms. Ultra-high molecular weight polyethylene (UHMW-PE) possess outstanding corrosion resistance, hydrophobicity, and chemical stability, which qualify it as a potential choice in soil adhesion reduction. Hence, this study aimed to investigate the feasibility of integrating a domed surface inspired by the micro-convex structure of the dung beetle skin with the UHMW-PE as a surface coating for soil engaging components in terms of soil adhesion reduction. The sliding resistance of three sliding plates (flat plate of carbon steel, flat plate of UHMW-PE, and domed plate of UHMW-PE), entirely identical in the projected area, was evaluated in two soil textures of silty clay and sandy clay loam, at four moisture levels of 18, 23, 28, and 33% and four drag speeds of 0.15, 0.2, 0.25, and 0.3 m s-1 using a completely randomized design. The dimensions of the embossed domes on the tested plate surface and their distribution pattern were established based on the previously published structural optimization of the bioinspired convex surface. In each treatment, the tested plate was dragged for 0.7 m of the soil bin length, and the sliding resistance was recorded continuously using the distributed stress and strain test and analysis system (DH3820 N). The coefficients of adhesion and friction were calculated according to the Mohr-Coulomb failure criterion. The variance analysis revealed that all investigated parameters significantly affected coefficients of adhesion and friction. In addition, as compared to flat steel plates, UHMW-PE coated plates exhibited much lower adhesion in all treatments, paving the way for practical applications in soil adhesion reduction and soilengaging component optimization.
土穴动物在粘性土壤中自由移动的能力是开发高效吸土工具的动力特征。据报道，土壤动物皮肤的疏水性和形态特征是产生其抗粘附机制的关键支柱。超高分子量聚乙烯(UHMW-PE)具有优异的耐腐蚀性、疏水性和化学稳定性，使其成为降低土壤附着力的潜在选择。因此，本研究旨在探讨将受屎壳虫皮肤微凸结构启发的圆顶表面与超高分子量聚乙烯(UHMW-PE)结合起来作为土壤粘附成分的表面涂层的可行性，以减少土壤的附着力。采用完全随机设计的方法，在粉质粘土和砂质粘土壤土两种土壤质地中，分别在18%、23%、28%和33%的水分水平和0.15、0.2、0.25和0.3 m s-1的阻力速度下，对投影区域完全相同的三种滑动板(碳钢平板、超高分子量聚乙烯平板和超高分子量聚乙烯圆顶板)的滑动阻力进行了评估。基于已发表的仿生凸面结构优化，确定了被测板表面浮雕圆顶的尺寸及其分布模式。在每次处理中，试验板被拖拽0.7 m的土仓长度，并使用DH3820 N分布式应力应变试验分析系统连续记录滑动阻力，根据Mohr-Coulomb破坏准则计算黏着系数和摩擦系数。方差分析表明，各参数对粘着系数和摩擦系数均有显著影响。此外，与扁平钢板相比，超高分子量聚乙烯涂层板在所有处理下的附着力都明显降低，为实际应用中降低土壤附着力和优化土壤粘附成分铺平了道路。
{"title":"The Effect of Integrating a Bio-Inspired Convex Structure with a Low-Surface Energy Polymer on Soil Adhesion and Friction","authors":"A. Salem, Guozhong Zhang, Hongchang Wang","doi":"10.56884/guln6927","DOIUrl":"https://doi.org/10.56884/guln6927","url":null,"abstract":"The capacity of soil-burrowing animals to move freely in sticky soil is a motivational trait for developing soil engaging tools with high operational efficiency. The hydrophobicity and morphological profiles of soil animals' skin were reported to be the key pillars in producing their anti-adhesive mechanisms. Ultra-high molecular weight polyethylene (UHMW-PE) possess outstanding corrosion resistance, hydrophobicity, and chemical stability, which qualify it as a potential choice in soil adhesion reduction. Hence, this study aimed to investigate the feasibility of integrating a domed surface inspired by the micro-convex structure of the dung beetle skin with the UHMW-PE as a surface coating for soil engaging components in terms of soil adhesion reduction. The sliding resistance of three sliding plates (flat plate of carbon steel, flat plate of UHMW-PE, and domed plate of UHMW-PE), entirely identical in the projected area, was evaluated in two soil textures of silty clay and sandy clay loam, at four moisture levels of 18, 23, 28, and 33% and four drag speeds of 0.15, 0.2, 0.25, and 0.3 m s-1 using a completely randomized design. The dimensions of the embossed domes on the tested plate surface and their distribution pattern were established based on the previously published structural optimization of the bioinspired convex surface. In each treatment, the tested plate was dragged for 0.7 m of the soil bin length, and the sliding resistance was recorded continuously using the distributed stress and strain test and analysis system (DH3820 N). The coefficients of adhesion and friction were calculated according to the Mohr-Coulomb failure criterion. The variance analysis revealed that all investigated parameters significantly affected coefficients of adhesion and friction. In addition, as compared to flat steel plates, UHMW-PE coated plates exhibited much lower adhesion in all treatments, paving the way for practical applications in soil adhesion reduction and soilengaging component optimization.","PeriodicalId":447600,"journal":{"name":"Proceedings of the 11th Asia-Pacific Regional Conference of the ISTVS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125418116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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